Unicast data transmission on a downlink common burst of a slot using mini-slots

ABSTRACT

A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may schedule a mini-slot for transmission of unicast data to a particular user equipment. The mini-slot may be scheduled in a portion of a downlink common burst portion of a slot. The apparatus may transmit a signal, including the unicast data, within the mini-slot.

CROSS REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application is a continuation of U.S. patent application Ser. No.16/810,072, filed Mar. 5, 2020, which is a continuation of U.S. patentapplication Ser. No. 15/693,025, filed Aug. 31, 2017, which claimspriority to U.S. Provisional Patent Application No. 62/443,397, filed onJan. 6, 2017, which are incorporated by reference herein.

BACKGROUND Field

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses forunicast data transmission on a downlink common burst of a slot usingmini-slots.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A UE may communicate with a BS via the downlink and uplink. Thedownlink (or forward link) refers to the communication link from the BSto the UE, and the uplink (or reverse link) refers to the communicationlink from the UE to the BS. As will be described in more detail herein,a BS may be referred to as a Node B, a gNB, an access point (AP), aradio head, a transmit receive point (TRP), a new radio (NR) BS, a 5GNode B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless communication devices to communicate on a municipal,national, regional, and even global level. New radio (NR), which mayalso be referred to as 5G, is a set of enhancements to the LTE mobilestandard promulgated by the Third Generation Partnership Project (3GPP).NR is designed to better support mobile broadband Internet access byimproving spectral efficiency, lowering costs, improving services,making use of new spectrum, and better integrating with other openstandards using OFDM with a cyclic prefix (CP) (CP-OFDM) on the downlink(DL), using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fouriertransform spread ODFM (DFT-s-OFDM)) on the uplink (UL), as well assupporting beamforming, multiple-input multiple-output (MIMO) antennatechnology, and carrier aggregation. However, as the demand for mobilebroadband access continues to increase, there exists a need for furtherimprovements in LTE and NR technologies. Preferably, these improvementsshould be applicable to other multiple access technologies and thetelecommunication standards that employ these technologies.

SUMMARY

In an aspect of the disclosure, a method, an apparatus, and a computerprogram product are provided.

In some aspects, the method may include scheduling, by a base station, amini-slot for transmission of unicast data to a particular userequipment (UE), wherein the mini-slot may be scheduled in a portion of adownlink (DL) common burst portion of a slot; and transmitting, by thebase station, a signal, including the unicast data, within themini-slot.

In some aspects, the apparatus may include one or more processorsconfigured to schedule a mini-slot for transmission of unicast data to aparticular UE, wherein the mini-slot may be scheduled in a portion of aDL common burst portion of a slot; and transmit a signal, including theunicast data, within the mini-slot.

In some aspects, the apparatus may include means for scheduling amini-slot for transmission of unicast data to a particular UE, whereinthe mini-slot may be scheduled in a portion of a DL common burst portionof a slot; and means for transmitting a signal, including the unicastdata, within the mini-slot.

In some aspects, the computer program product may include anon-transitory computer-readable medium storing computer executablecode. The code may include code for scheduling a mini-slot fortransmission of unicast data to a particular UE, wherein the mini-slotmay be scheduled in a portion of a DL common burst portion of a slot;and code for transmitting a signal, including the unicast data, withinthe mini-slot.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, base station, userequipment, wireless communication device, and processing system assubstantially described herein with reference to and as illustrated bythe accompanying drawings.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is diagram| illustrating an example of a wireless communicationnetwork.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a user equipment (UE) in a wireless communicationnetwork.

FIG. 3 is a diagram illustrating an example of a frame structure in awireless communication network.

FIG. 4 is a diagram illustrating two example subframe formats with thenormal cyclic prefix.

FIG. 5 is a diagram illustrating an example logical architecture of adistributed radio access network (RAN).

FIG. 6 is a diagram illustrating an example physical architecture of adistributed RAN.

FIG. 7A is a diagram illustrating an example of a downlink (DL)-centricwireless communication structure.

FIG. 7B is a diagram illustrating an example of a downlink (DL)-centricwireless communication structure that includes one or more mini-slotswithin a downlink common burst portion of the wireless communicationstructure.

FIG. 8A is a diagram illustrating an example of an uplink (UL)-centricwireless communication structure.

FIG. 8B is a diagram illustrating an example of an uplink (UL)-centricwireless communication structure that that includes one or moremini-slots within a downlink common burst portion of the wirelesscommunication structure.

FIG. 9 is a diagram illustrating an example of scheduling a mini-slotfor transmitting unicast data in a portion of a downlink common burstportion of a slot, and transmitting the unicast data within themini-slot.

FIG. 10 is a flow chart of a method of wireless communication.

FIG. 11 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an example apparatus.

FIG. 12 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purposes of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well-known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, and/or the like (collectivelyreferred to as “elements”). These elements may be implemented usingelectronic hardware, computer software, or any combination thereof.Whether such elements are implemented as hardware or software dependsupon the particular application and design constraints imposed on theoverall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions,and/or the like, whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software, the functions may be stored on orencoded as one or more instructions or code on a computer-readablemedium. Computer-readable media includes computer storage media. Storagemedia may be any available media that can be accessed by a computer. Byway of example, and not limitation, such computer-readable media cancomprise a random-access memory (RAM), a read-only memory (ROM), anelectrically erasable programmable ROM (EEPROM), compact disk ROM(CD-ROM) or other optical disk storage, magnetic disk storage or othermagnetic storage devices, combinations of the aforementioned types ofcomputer-readable media, or any other medium that can be used to storecomputer executable code in the form of instructions or data structuresthat can be accessed by a computer.

An access point (“AP”) may comprise, be implemented as, or known as aNodeB, a Radio Network Controller (“RNC”), an eNodeB (eNB), a BaseStation Controller (“BSC”), a Base Transceiver Station (“BTS”), a BaseStation (“BS”), a Transceiver Function (“TF”), a Radio Router, a RadioTransceiver, a Basic Service Set (“BSS”), an Extended Service Set(“ESS”), a Radio Base Station (“RBS”), a Node B (NB), a gNB, a 5G NB, aNR BS, a Transmit Receive Point (TRP), or some other terminology.

An access terminal (“AT”) may comprise, be implemented as, or be knownas an access terminal, a subscriber station, a subscriber unit, a mobilestation, a remote station, a remote terminal, a user terminal, a useragent, a user device, user equipment (UE), a user station, a wirelessnode, or some other terminology. In some aspects, an access terminal maycomprise a cellular telephone, a smart phone, a cordless telephone, aSession Initiation Protocol (“SIP”) phone, a wireless local loop (“WLL”)station, a personal digital assistant (“PDA”), a tablet, a netbook, asmartbook, an ultrabook, a handheld device having wireless connectioncapability, a Station (“STA”), or some other suitable processing deviceconnected to a wireless modem. Accordingly, one or more aspects taughtherein may be incorporated into a phone (e.g., a cellular phone, a smartphone), a computer (e.g., a desktop), a portable communication device, aportable computing device (e.g., a laptop, a personal data assistant, atablet, a netbook, a smartbook, an ultrabook), wearable device (e.g.,smart watch, smart glasses, smart bracelet, smart wristband, smart ring,smart clothing, and/or the like), medical devices or equipment,biometric sensors/devices, an entertainment device (e.g., music device,video device, satellite radio, gaming device, and/or the like), avehicular component or sensor, smart meters/sensors, industrialmanufacturing equipment, a global positioning system device, or anyother suitable device that is configured to communicate via a wirelessor wired medium. In some aspects, the node is a wireless node. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as the Internet or a cellular network)via a wired or wireless communication link. Some UEs may be consideredmachine-type communication (MTC) UEs, which may include remote devicesthat may communicate with a base station, another remote device, or someother entity. Machine type communications (MTC) may refer tocommunication involving at least one remote device on at least one endof the communication and may include forms of data communication whichinvolve one or more entities that do not necessarily need humaninteraction. MTC UEs may include UEs that are capable of MTCcommunications with MTC servers and/or other MTC devices through PublicLand Mobile Networks (PLMN), for example. Examples of MTC devicesinclude sensors, meters, location tags, monitors, drones, robots/roboticdevices, and/or the like. MTC UEs, as well as other types of UEs, may beimplemented as NB-IoT (narrowband internet of things) devices.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 5G or NR network.Wireless network 100 may include a number of BSs 110 (shown as BS 110 a,BS 110 b, BS 110 c, and BS 110 d) and other network entities. A BS is anentity that communicates with user equipment (UEs) and may also bereferred to as a base station, a NR BS, a Node B, a gNB, a 5G NB, anaccess point, a TRP, and/or the like. Each BS may provide communicationcoverage for a particular geographic area. In 3GPP, the term “cell” canrefer to a coverage area of a BS and/or a BS subsystem serving thiscoverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some examples, the BSs may be interconnected to oneanother and/or to one or more other BSs or network nodes (not shown) inthe access network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impact on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium. Some UEs may be considered evolved or enhancedmachine-type communication (eMTC) UEs. MTC and eMTC UEs include, forexample, robots, drones, remote devices, such as sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices. Some UEs may be considereda Customer Premises Equipment (CPE).

In FIG. 1 , a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates potentially interfering transmissions between a UE anda BS.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, NR or 5G RAT networks may be deployed.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within thescheduling entity's service area or cell. Within the present disclosure,as discussed further below, the scheduling entity may be responsible forscheduling, assigning, reconfiguring, and releasing resources for one ormore subordinate entities. That is, for scheduled communication,subordinate entities utilize resources allocated by the schedulingentity.

Base stations are not the only entities that may function as ascheduling entity. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more subordinateentities (e.g., one or more other UEs). In this example, the UE isfunctioning as a scheduling entity, and other UEs utilize resourcesscheduled by the UE for wireless communication. A UE may function as ascheduling entity in a peer-to-peer (P2P) network, and/or in a meshnetwork. In a mesh network example, UEs may optionally communicatedirectly with one another in addition to communicating with thescheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1 .

FIG. 2 shows a block diagram of a design of base station 110 and UE 120,which may be one of the base stations and one of the UEs in FIG. 1 .Base station 110 may be equipped with T antennas 234 a through 234 t,and UE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI), and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the CRS) and synchronization signals (e.g., the primarysynchronization signal (PSS) and secondary synchronization signal(SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230 may perform spatial processing (e.g., precoding) on the datasymbols, the control symbols, the overhead symbols, and/or the referencesymbols, if applicable, and may provide T output symbol streams to Tmodulators (MODs) 232 a through 232 t. Each modulator 232 may process arespective output symbol stream (e.g., for OFDM and/or the like) toobtain an output sample stream. Each modulator 232 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. T downlink signals frommodulators 232 a through 232 t may be transmitted via T antennas 234 athrough 234 t, respectively. According to certain aspects described inmore detail below, the synchronization signals can be generated withlocation encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine RSRP, RSSI, RSRQ, CQI, and/or the like.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

Controllers/processors 240 and 280 and/or any other component(s) in FIG.2 may direct the operation at base station 110 and UE 120, respectively,to perform unicast data transmission on a downlink common burst of aslot using a mini-slot. For example, controller/processor 280 and/orother processors and modules at base station 110, may perform or directoperations of UE 120 to perform unicast data transmission on a downlinkcommon burst of a slot using a mini-slot. For example,controller/processor 280 and/or other controllers/processors and modulesat BS 110 may perform or direct operations of, for example, process 1000of FIG. 10 and/or other processes as described herein. In some aspects,one or more of the components shown in FIG. 2 may be employed to performexample process 1000 of FIG. 10 and/or other processes for thetechniques described herein. Memories 242 and 282 may store data andprogram codes for BS 110 and UE 120, respectively. A scheduler 246 mayschedule UEs for data transmission on the downlink and/or uplink.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2 .

FIG. 3 shows an example frame structure 300 for FDD in atelecommunications system (e.g., LTE). The transmission timeline foreach of the downlink and uplink may be partitioned into units of radioframes. Each radio frame may have a predetermined duration (e.g., 10milliseconds (ms)) and may be partitioned into 10 subframes with indicesof 0 through 9. Each subframe may include two slots. Each radio framemay thus include 20 slots with indices of 0 through 19. Each slot mayinclude L symbol periods, e.g., seven symbol periods for a normal cyclicprefix (as shown in FIG. 3 ) or six symbol periods for an extendedcyclic prefix. The 2L symbol periods in each subframe may be assignedindices of 0 through 2L-1.

While some techniques are described herein in connection with frames,subframes, slots, and/or the like, these techniques may equally apply toother types of wireless communication structures, which may be referredto using terms other than “frame,” “subframe,” “slot,” and/or the likein 5G NR. In some aspects, a wireless communication structure may referto a periodic time-bounded communication unit defined by a wirelesscommunication standard and/or protocol.

In certain telecommunications (e.g., LTE), a BS may transmit a primarysynchronization signal (PSS) and a secondary synchronization signal(SSS) on the downlink in the center of the system bandwidth for eachcell supported by the BS. The PSS and SSS may be transmitted in symbolperiods 6 and 5, respectively, in subframes 0 and 5 of each radio framewith the normal cyclic prefix, as shown in FIG. 3 . The PSS and SSS maybe used by UEs for cell search and acquisition. The BS may transmit acell-specific reference signal (CRS) across the system bandwidth foreach cell supported by the BS. The CRS may be transmitted in certainsymbol periods of each subframe and may be used by the UEs to performchannel estimation, channel quality measurement, and/or other functions.The BS may also transmit a physical broadcast channel (PBCH) in symbolperiods 0 to 3 in slot 1 of certain radio frames. The PBCH may carrysome system information. The BS may transmit other system informationsuch as system information blocks (SIBs) on a physical downlink sharedchannel (PDSCH) in certain subframes. The BS may transmit controlinformation/data on a physical downlink control channel (PDCCH) in thefirst B symbol periods of a subframe, where B may be configurable foreach subframe. The BS may transmit traffic data and/or other data on thePDSCH in the remaining symbol periods of each subframe.

In other systems (e.g., such NR or 5G systems), a Node B may transmitthese or other signals in these locations or in different locations ofthe subframe.

As indicated above, FIG. 3 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 3 .

FIG. 4 shows two example subframe formats 410 and 420 with the normalcyclic prefix. The available time frequency resources may be partitionedinto resource blocks. Each resource block may cover 12 subcarriers inone slot and may include a number of resource elements. Each resourceelement may cover one subcarrier in one symbol period and may be used tosend one modulation symbol, which may be a real or complex value.

Subframe format 410 may be used for two antennas. A CRS may betransmitted from antennas 0 and 1 in symbol periods 0, 4, 7 and 11. Areference signal is a signal that is known a priori by a transmitter anda receiver and may also be referred to as pilot. A CRS is a referencesignal that is specific for a cell, e.g., generated based at least inpart on a cell identity (ID). In FIG. 4 , for a given resource elementwith label Ra, a modulation symbol may be transmitted on that resourceelement from antenna a, and no modulation symbols may be transmitted onthat resource element from other antennas. Subframe format 420 may beused with four antennas. A CRS may be transmitted from antennas 0 and 1in symbol periods 0, 4, 7 and 11 and from antennas 2and 3 in symbolperiods 1 and 8. For both subframe formats 410 and 420, a CRS may betransmitted on evenly spaced subcarriers, which may be determined basedat least in part on cell ID. CRSs may be transmitted on the same ordifferent subcarriers, depending on their cell IDs. For both subframeformats 410 and 420, resource elements not used for the CRS may be usedto transmit data (e.g., traffic data, control data, and/or other data).

The PSS, SSS, CRS and PBCH in LTE are described in 3GPP TS 36.211,entitled “Evolved Universal Terrestrial Radio Access (E-UTRA); PhysicalChannels and Modulation,” which is publicly available.

An interlace structure may be used for each of the downlink and uplinkfor FDD in certain telecommunications systems (e.g., LTE). For example,Q interlaces with indices of 0 through Q-1 may be defined, where Q maybe equal to 4, 6, 8, 10, or some other value. Each interlace may includesubframes that are spaced apart by Q frames. In particular, interlace qmay include subframes q, q+Q, q+2Q, and/or the like, where q∈{0, . . . ,Q-1}.

The wireless network may support hybrid automatic repeat request (HARQ)for data transmission on the downlink and uplink. For HARQ, atransmitter (e.g., a BS) may send one or more transmissions of a packetuntil the packet is decoded correctly by a receiver (e.g., a UE) or someother termination condition is encountered. For synchronous HARQ, alltransmissions of the packet may be sent in subframes of a singleinterlace. For asynchronous HARQ, each transmission of the packet may besent in any subframe.

A UE may be located within the coverage of multiple BSs. One of theseBSs may be selected to serve the UE. The serving BS may be selectedbased at least in part on various criteria such as received signalstrength, received signal quality, path loss, and/or the like. Receivedsignal quality may be quantified by a signal-to-noise-and-interferenceratio (SINR), or a reference signal received quality (RSRQ), or someother metric. The UE may operate in a dominant interference scenario inwhich the UE may observe high interference from one or more interferingBSs.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communication systems, such as NR or 5Gtechnologies.

New radio (NR) may refer to radios configured to operate according to anew air interface (e.g., other than Orthogonal Frequency DivisionalMultiple Access (OFDMA)-based air interfaces) or fixed transport layer(e.g., other than Internet Protocol (IP)). In aspects, NR may utilizeOFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM)and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink andinclude support for half-duplex operation using TDD. In aspects, NR may,for example, utilize OFDM with a CP (herein referred to as CP-OFDM)and/or discrete Fourier transform spread orthogonal frequency-divisionmultiplexing (DFT-s-OFDM) on the uplink, may utilize CP-OFDM on thedownlink and include support for half-duplex operation using TDD. NR mayinclude Enhanced Mobile Broadband (eMBB) service targeting widebandwidth (e.g., 80 megahertz (MHz) and beyond), millimeter wave (mmW)targeting high carrier frequency (e.g., 60 gigahertz (GHz)), massive MTC(mMTC) targeting non-backward compatible MTC techniques, and/or missioncritical targeting ultra reliable low latency communications (URLLC)service.

A single component carrier bandwidth of 100 MHZ may be supported. NRresource blocks may span 12 sub-carriers with a sub-carrier bandwidth of75 kilohertz (kHz) over a 0.1 ms duration. Each radio frame may include50 subframes with a length of 10 ms. Consequently, each subframe mayhave a length of 0.2 ms. Each subframe may indicate a link direction(e.g., DL or UL) for data transmission and the link direction for eachsubframe may be dynamically switched. Each subframe may include DL/ULdata as well as DL/UL control data. UL and DL slots of subframes for NRmay be as described in more detail below with respect to FIGS. 7A, 7B,8A, and 8B.

Beamforming may be supported and beam direction may be dynamicallyconfigured. MIMO transmissions with precoding may also be supported.MIMO configurations in the DL may support up to 8 transmit antennas withmulti-layer DL transmissions up to 8 streams and up to 2 streams per UE.Multi-layer transmissions with up to 2 streams per UE may be supported.Aggregation of multiple cells may be supported with up to 8 servingcells. Alternatively, NR may support a different air interface, otherthan an OFDM-based interface. NR networks may include entities suchcentral units or distributed units.

The RAN may include a central unit (CU) and distributed units (DUs). ANR BS (e.g., gNB, 5G Node B, Node B, transmit receive point (TRP),access point (AP)) may correspond to one or multiple BSs. NR cells canbe configured as access cells (ACells) or data only cells (DCells). Forexample, the RAN (e.g., a central unit or distributed unit) canconfigure the cells. DCells may be cells used for carrier aggregation ordual connectivity, but not used for initial access, cellselection/reselection, or handover. In some cases, DCells may nottransmit synchronization signals—in some case cases DCells may transmitSS. NR BSs may transmit downlink signals to UEs indicating the celltype. Based at least in part on the cell type indication, the UE maycommunicate with the NR BS. For example, the UE may determine NR BSs toconsider for cell selection, access, handover, and/or measurement basedat least in part on the indicated cell type.

As indicated above, FIG. 4 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 4 .

FIG. 5 illustrates an example logical architecture of a distributed RAN500, according to aspects of the present disclosure. A 5G access node506 may include an access node controller (ANC) 502. The ANC may be acentral unit (CU) of the distributed RAN 500. The backhaul interface tothe next generation core network (NG-CN) 504 may terminate at the ANC.The backhaul interface to neighboring next generation access nodes(NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs508 (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs,gNB, or some other term). As described above, a TRP may be usedinterchangeably with “cell.”

The TRPs 508 may be a distributed unit (DU). The TRPs may be connectedto one ANC (ANC 502) or more than one ANC (not illustrated). Forexample, for RAN sharing, radio as a service (RaaS), and servicespecific AND deployments, the TRP may be connected to more than one ANC.A TRP may include one or more antenna ports. The TRPs may be configuredto individually (e.g., dynamic selection) or jointly (e.g., jointtransmission) serve traffic to a UE.

The local architecture of RAN 500 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based at least in part on transmit networkcapabilities (e.g., bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 510 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 508. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 502. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture of RAN 500. The PDCP, RLC, MACprotocol may be adaptably placed at the ANC or TRP.

According to certain aspects, a BS may include a central unit (CU)(e.g., ANC 502) and/or one or more distributed units (e.g., one or moreTRPs 508).

As indicated above, FIG. 5 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 5 .

FIG. 6 illustrates an example physical architecture of a distributed RAN600, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 602 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 604 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A distributed unit (DU) 606 may host one or more TRPs. The DU may belocated at edges of the network with radio frequency (RF) functionality.

As indicated above, FIG. 6 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 6 .

FIG. 7A is a diagram 700 showing an example of a DL-centric wirelesscommunication structure. The DL-centric wireless communication structure(referred to hereinafter as a DL-centric slot) may include a controlportion 702. The control portion 702 may exist in the initial orbeginning portion of the DL-centric slot. The control portion 702 mayinclude various scheduling information and/or control informationcorresponding to various portions of the DL-centric slot. In someconfigurations, the control portion 702 may be a physical DL controlchannel (PDCCH), as indicated in FIG. 7A.

The DL-centric slot may also include a DL data portion 704. The DL dataportion 704 may sometimes be referred to as the payload of theDL-centric slot. The DL data portion 704 may include the communicationresources utilized to communicate DL data from the scheduling entity(e.g., UE or BS) to the subordinate entity (e.g., UE). In someconfigurations, the DL data portion 704 may be a physical DL sharedchannel (PDSCH).

The DL-centric slot may also include an UL short burst portion 706. TheUL short burst portion 706 may sometimes be referred to as an UL burst,an UL burst portion, a common UL burst, a short burst, an UL shortburst, a common UL short burst, a common UL short burst portion, and/orvarious other suitable terms. In some aspects, the UL short burstportion 706 may include one or more reference signals. Additionally, oralternatively, the UL short burst portion 706 may include feedbackinformation corresponding to various other portions of the DL-centricslot. For example, the UL short burst portion 706 may include feedbackinformation corresponding to the control portion 702 and/or the dataportion 704. Non-limiting examples of information that may be includedin the UL short burst portion 706 include an ACK signal (e.g., a PUCCHACK, a PUSCH ACK, an immediate ACK), a NACK signal (e.g., a PUCCH NACK,a PUSCH NACK, an immediate NACK), a scheduling request (SR), a bufferstatus report (BSR), a HARQ indicator, a channel state indication (CSI),a channel quality indicator (CQI), a sounding reference signal (SRS), ademodulation reference signal (DMRS), PUSCH data, and/or various othersuitable types of information. The UL short burst portion 706 mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests, and various other suitable types of information.

As illustrated in FIG. 7A, the end of the DL data portion 704 may beseparated in time from the beginning of the UL short burst portion 706.This time separation may sometimes be referred to as a gap, a guardperiod, a guard interval, and/or various other suitable terms. Thisseparation provides time for the switch-over from DL communication(e.g., reception operation by the subordinate entity (e.g., UE)) to ULcommunication (e.g., transmission by the subordinate entity (e.g., UE)).The foregoing is merely one example of a DL-centric wirelesscommunication structure, and alternative structures having similarfeatures may exist without necessarily deviating from the aspectsdescribed herein.

In some aspects, the DL-centric slot may include one or more mini-slotsin, for example, the control portion 702. FIG. 7B is a diagram 750illustrating an example of a DL-centric slot that includes one or moremini-slots 708 within the control portion 702 (sometimes referred to asa DL common burst portion 702) of the DL-centric slot.

The mini-slot 708 is a unit of scheduling in NR that is smaller than aslot (i.e., a portion of the slot). For example, while an enhancedmobile broadband (eMBB) slot may include 14 symbols, the mini-slot 708may include fewer than 14 symbols (e.g., one symbol, two symbols, foursymbols, and/or the like). In some aspects, the mini-slot 708 mayinclude one or more data symbols that represent data.

Additionally, or alternatively, the mini-slot 708 may include one ormore control symbols that represent control information associated withthe mini-slot 708. In some aspects, the one or more control symbols maybe at or near a beginning of the mini-slot 708 (e.g., in the first twosymbols of the mini-slot) or at or near an end of the mini-slot 708(e.g., in the last symbol of the mini-slot.) Alternatively, themini-slot 708 may not include a control symbol.

Additionally, or alternatively, the mini-slot 708 may include areference symbol that carries information associated with demodulatingdata included in the mini-slot 708 (e.g., a DMRS). In some aspects, thereference symbol may be at any location within the mini-slot 708 (e.g.,in a first symbol, a last symbol, and/or the like). In some aspects, thereference symbol and the control symbol may be the same symbol (i.e., asingle symbol may carry the control information and the informationassociated with demodulating data included in the mini-slot 708).

In some aspects, the inclusion of the reference symbol in the mini-slot708 may permit a reference symbol to be omitted from a portion of the DLdata portion 704. For example, assume that the mini-slot 708 carriesfirst data destined for a particular UE and the portion of the DL dataportion 704, that uses a same frequency band as the mini-slot 708,carries second data destined for the particular UE. Here, if themini-slot 708 includes the reference symbol, then the portion of the DLdata portion 704 may not include the reference symbol. In this example,the particular UE may use the reference symbol included in the mini-slot708 to demodulate the second data carried in the portion of the DL dataportion 704. Omitting the reference symbol from the portion of the DLdata portion 704 may provide for reduced latency since the particular UEmay demodulate, and thereafter acknowledge, receipt of the second datawithout buffering the second data carried in the portion of the DL dataportion 704.

Alternatively, the mini-slot 708 may not include a reference symbol. Forexample, assume that the mini-slot 708 carries first data destined for aparticular UE, and a portion of the DL data portion 704 that uses a samefrequency band as the mini-slot 708 carries second data destined for theparticular UE. Here, the mini-slot 708 may not include the referencesymbol when the reference symbol is included in the portion of the DLdata portion 704 that carries the second data. In this example, theparticular UE may buffer the first data carried in the mini-slot 708,and demodulate the first data after receiving the reference symbol inthe portion of the DL data portion 704. Omitting the reference symbolfrom the mini-slot 708 may provide for improved robustness to mobilityof the particular UE since the reference symbol is received later (e.g.,near the middle) of the transmission of the first data and the seconddata to the particular UE.

In some aspects, the mini-slot 708 may have a subcarrier spacing that isthe same as a subcarrier spacing of the slot in which the mini-slot 708is included. Alternatively, the mini-slot 708 may have a subcarrierspacing that differs from the subcarrier spacing of the slot in whichthe mini-slot 708 is included. In some aspects, increasing thesubcarrier spacing of the mini-slot 708 relative to the subcarrierspacing of the slot may allow for additional symbols to be included inthe mini-slot 708. For example, if the mini-slot 708 has a samesubcarrier spacing as the slot (e.g., 30 kilohertz (kHz)), then themini-slot 708 may include a particular number of symbols (e.g., 2symbols). However, if the mini-slot 708 has a subcarrier spacing that isgreater than (e.g., two times) the subcarrier spacing (e.g., 2×30 kHz=60kHz), then the mini-slot 708 may include a greater number (e.g., twotimes) the particular number of symbols (e.g., 2×2 symbols=4 symbols).

In some aspects, a parameter, associated with transmitting data in themini-slot 708, may be different than a parameter associated withtransmitting data in the DL data portion 704. For example, a MCSassociated with data included in the mini-slot 708 (e.g., a modulationorder, a coding rate, a HARQ configuration, and/or the like) may bedifferent from a MCS associated with data included in the DL dataportion 704. As another example, a number of MIMO layers, associatedwith the data included in the mini-slot 708, may be different from anumber of MIMO layers associated with the data included in the DL dataportion 704.

As shown in FIG. 7B, in some aspects, a mini-slot 708 may be included inthe control portion 702 (i.e., the DL common burst portion 702) of theDL-centric slot. In some aspects, the mini-slot 708 may be used totransmit data to a particular UE. As such, in some aspects, the minislot 708 may include unicast data (e.g., data destined for a particularUE), while the remainder of the control portion 702 may includebroadcast data (e.g., data destined for multiple UEs). In other words,the portion of the control portion 702 used for mini-slot 708 mayinclude unicast data, whereas the control portion 702 includes broadcastor multicast data.

In some aspects, the mini-slot 708 may be associated with transmittingdata to a particular UE and may utilize one or more ranges offrequencies. For example, the mini-slot 708 may utilize a particularrange of frequencies of the slot (e.g., a highest 30 megahertz (MHz)when a slot has a range of 80 MHz) to transmit data to the particularUE, while the DL common burst portion 702 may utilize a different rangeof frequencies of the slot (e.g., the remaining 60 MHz of the 80 MHzslot) to transmit control information to multiple UEs. As anotherexample, the mini-slot 708 may utilize a first range of frequencies ofthe slot (e.g., the highest 30 MHz of the 80 MHz slot range) and asecond range of frequencies of the slot (e.g., a lowest 30 MHz of the 80MHz slot range) to transmit data to the particular UE, while the DLcommon burst portion 702 may utilize a third range of frequencies of theslot (e.g., a middle 20 MHz of the 80 MHz slot) to transmit controlinformation to multiple UEs. In some aspects, as shown in FIG. 7B, thefirst range of frequencies may be separated from the second range offrequencies by the third range of frequencies.

Additionally, or alternatively, different mini-slots 708 may beassociated with transmitting data to different UEs and may utilizedifferent ranges of frequencies. For example, a first mini-slot 708 mayutilize a first range of frequencies of the slot (e.g., the highest 30MHz of the 80 MHz slot range) to transmit first data to a firstparticular UE, while a second mini-slot 708 may utilize a second rangeof frequencies of the slot (e.g., the lowest 30 MHz of the 80 MHz slotrange) to transmit second data to a second particular UE. Here, the DLcommon burst portion 702 may utilize a third range of frequencies of theslot (e.g., the middle 20 MHz of the 80 MHz slot) to transmit controlinformation to multiple UEs.

The foregoing is merely one example of an UL-centric wirelesscommunication structure that includes one or more mini-slots andalternative structures having similar features may exist withoutnecessarily deviating from the aspects described herein. Detailsregarding scheduling of mini-slots 708 within a DL-centric slot fortransmission of unicast data to a particular UE are described below.

As indicated above, FIGS. 7A and 7B are provided merely as examples.Other examples are possible and may differ from what was described withregard to FIGS. 7A and 7B. Further, while FIGS. 7A and 7B are DL-centricslots may be used for NR technology, another type of radio accesstechnology (e.g., LTE) may use a subframe for a similar purpose and/orin a similar manner as that described in association with the DL-centricslots of FIGS. 7A and 7B.

FIG. 8A is a diagram 800 showing an example of an UL-centric wirelesscommunication structure. The UL-centric wireless communication structure(referred to hereinafter as an UL-centric slot) may include a controlportion 802. The control portion 802 may exist in the initial orbeginning portion of the UL-centric slot. The control portion 802 inFIG. 8A may be similar to the control portion 702 described above withreference to FIG. 7A. In some configurations, the control portion 802(sometimes referred to as DL common burst portion 802) may be a physicalDL control channel (PDCCH).

The UL-centric slot may also include an UL long burst portion 804. TheUL long burst portion 804 may sometimes be referred to as the payload ofthe UL-centric slot. The UL long burst portion 804 may refer to thecommunication resources utilized to communicate UL data from thesubordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS).

As illustrated in FIG. 8A, the end of the control portion 802 may beseparated in time from the beginning of the UL long burst portion 804.This time separation may sometimes be referred to as a gap, guardperiod, guard interval, and/or various other suitable terms. Thisseparation provides time for the switch-over from DL communication(e.g., reception operation by the scheduling entity) to UL communication(e.g., transmission by the scheduling entity).

The UL-centric slot may also include an UL short burst portion 806. TheUL short burst portion 806 in FIG. 8A may be similar to the UL shortburst portion 706 described above with reference to FIG. 7A, and mayinclude any of the information described above in connection with FIG.7A. The foregoing is merely one example of an UL-centric wirelesscommunication structure and alternative structures having similarfeatures may exist without necessarily deviating from the aspectsdescribed herein.

In some aspects, the UL-centric slot may include one or more mini-slotsin, for example, the control portion 802. FIG. 8B is a diagram 850illustrating an example of a UL-centric slot that includes one or moremini-slots 808 within the control portion 802 (sometimes referred to asa DL common burst portion 802) of the UL-centric slot. The mini-slot 808in FIG. 8B may be similar to the mini-slot 708 described above withreference to FIG. 7B, and may include any information described inconnection with FIG. 7B. The foregoing is merely one example of anUL-centric wireless communication structure that includes one or moremini-slots, and alternative structures having similar features may existwithout necessarily deviating from the aspects described herein. Detailsregarding scheduling of mini-slots 808 within a UL-centric slot fortransmission of unicast data to a particular UE are described below.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

In one example, a wireless communication structure, such as a frame, mayinclude both UL-centric slots and DL-centric slots. In this example, theratio of UL-centric slots to DL-centric slots in a frame may bedynamically adjusted based at least in part on the amount of UL data andthe amount of DL data that are transmitted. For example, if there ismore UL data, then the ratio of UL-centric slots to DL-centric slots maybe increased. Conversely, if there is more DL data, then the ratio ofUL-centric slots to DL-centric slots may be decreased.

As indicated above, FIGS. 8A and 8B are provided merely as examples.Other examples are possible and may differ from what was described withregard to FIGS. 8A and 8B. Further, while FIGS. 8A and 8B are UL-centricslots that may be used for NR technology, another type of radio accesstechnology (e.g., LTE) may use a subframe for a similar purpose and/orin a similar manner as that described in association with the UL-centricslots of FIGS. 8A and 8B.

As described above, a control portion of a slot (e.g., control portion702 or control portion 802 of a DL-centric slot or an UL-centric slot,respectively) may include one or more mini-slots (e.g., mini-slots 708or 808) for transmitting data (e.g., unicast data) to a particular UE.Use of the mini-slots within the control portion to transmit such datamay permit a latency and/or a reliability requirement of a service(e.g., a low latency service, an ultra-reliable low-latencycommunication (URLLC) service, and/or the like) to be satisfied withoutimpacting network performance. For example, when the control portion ofthe slot utilizes only a portion of the control portion (e.g., a middle20 MHz of an 80 MHz range), use of one or more other portions of thecontrol portion as mini-slots to transmit URLLC data to a particular UEmay improve the URLLC service, as provided to the particular UE, byallowing for reduced latency and/or improved reliability (withoutnegatively impacting network performance). In some aspects, BS 110 mayschedule such mini-slots for transmissions of unicast data withinDL-centric and/or UL-centric slots.

In some aspects, the mini-slots may be used for service that requires(e.g., due to a HARQ configuration of the particular UE 120) anacknowledgement (e.g., an ACK) to be transmitted in a same slot as adata transmission. Here, BS 110 may schedule a mini-slot for atransmission to the particular UE 120 (e.g., UE 120 with the HARQconfiguration) in order to allow the particular UE 120 to provide anacknowledgment in the same slot. Notably, BS 110 can schedule data onthe data portion of the slot, but a service requiring the same-slotacknowledgment may need to be scheduled on the mini-slot depending onHARQ configurations supported by the particular UE 120. For example, ifthe particular UE 120 does not support transmitting a same-slotacknowledgement for data received in the data portion of the slot, butis capable of doing so for the mini-slot, then BS 110 should schedulethe data for transmission in the mini-slot.

FIG. 9 is a diagram illustrating an example 900 of scheduling amini-slot for transmitting data in a portion of a DL common burstportion of a slot, and transmitting the data within the mini-slot.Notably, while example 900 describes techniques associated withscheduling a mini-slot within a DL-centric slot, these techniques may besimilarly applied in association with scheduling a mini-slot within anUL-centric slot.

As shown in FIG. 9 , and by reference number 905, BS 110 may identifycontrol information that includes information associated with one ormore transmissions of data within a slot. The control information mayinclude, for example, information that identifies a set of radioresources corresponding to one or more transmissions of data within DLdata portion the slot (i.e., a set of radio resources corresponding toeach transmission in the DL data portion), information that identifiesUEs 120 associated with each of the one or more transmissions in the DLdata portion of the slot, and/or the like. In some aspects, such controlinformation allows each UE 120 to identify radio resources, within theDL data portion, that include data destined for the UE 120.

In some aspects, the control information may include informationassociated with one or more mini-slots, where each mini-slot may be usedto transmit data to a different particular UE 120.

Additionally, or alternatively, the control information may includeinformation that identifies a set of radio resources corresponding toone or more transmissions of data in a mini-slot in the control portionof the slot (i.e., a set of radio resources in the control portion thatwill be used to transmit the data), information that identifies aparticular UE 120 to which the data is to be transmitted, and/or thelike. In some aspects, such control information allows the particular UE120 to determine that BS 110 will transmit data to the particular UE 120using the mini-slot, included in the control portion of the slot, thatis described by the control information.

In some aspects, the particular UE 120 for which a mini-slot isscheduled may have a portion of a DL data portion 704 scheduled foranother transmission to the particular UE 120. Alternatively, theparticular UE 120 for which a mini-slot is scheduled may not have aportion of a DL data portion 704 scheduled for another transmission tothe particular UE 120 (i.e., the particular UE 120 may be scheduled fora transmission using only the mini-slot).

In some aspects, BS 110 may determine the control information based on ascheduler of BS 110 (e.g., scheduler 246) that schedules UEs 120 fordata transmissions on the downlink and/or uplink.

As shown by reference number 910, BS 110 may transmit the controlinformation within a control portion of a DL common burst. For example,BS 110 may transmit the control information within a portion of controlportion 702 (i.e., a DL common burst) of a DL-centric slot. As anotherexample, BS 110 may transmit the control information within a portion ofcontrol portion 802 (i.e., a DL common burst) of an UL-centric slot.

In some aspects, as described above, the portion of the DL common burstused to transmit the control information may be less than the entire DLcommon burst portion of the slot. For example, BS 110 may transmit thecontrol information using radio resources associated with a particularrange of frequencies that is less than an entire range of frequenciesassociated with the slot (e.g., a middle 20 kHz of an 80 kHz slot).

In this way, BS 110 may schedule the mini-slot for transmission of datato the particular UE in a portion of a DL common burst of a slot.

As further shown in FIG. 9 , and by reference number 915, BS 110 maytransmit a signal including the data (sometimes referred to astransmitting the data), destined for the particular UE 120, within themini-slot (e.g., using other radio resources corresponding of themini-slot) of the DL common burst portion of the slot.

In some aspects, BS 110 may transmit the control information and themini-slot data in a same slot (i.e., within a same DL common burst of aDL-centric or UL-centric slot). Additionally, or alternatively, BS 110may transmit the control information in a first slot (e.g., a within aDL common burst portion of a DL-centric or UL-centric slot) and maytransmit the signal including mini-slot data in a second slot (e.g.,within a DL common burst portion of a subsequent DL-centric orUL-centric slot).

As described above, in some aspects, BS 110 may transmit a DMRS withinthe mini-slot, or may transmit the DMRS within a DL data portion of theslot (e.g., when the portion of the DL data portion that uses a samefrequency band as the mini-slot carries additional data destined for theparticular UE 120).

In some aspects, in the case of DL-centric slot, BS 110 may transmit asignal including other data in the DL data portion of the slot (e.g.,after transmitting the control information and the mini-slot data in theDL common burst) in the typical manner. In the case of an UL-centricslot, BS 110 may await receipt of UL data, transmitted by UEs 120 in theUL data portion of the UL-centric slot.

As shown by reference number 920, the particular UE 120 may receive thecontrol information transmitted by BS 110 in the DL common burst. Insome aspects, the particular UE 120 may process the control informationand identify, based at least in part on the control information, thatthe mini-slot is being used to transmit data to the particular UE 120(e.g., within the same slot or a subsequent slot). In this way, theparticular UE 120 may determine that the mini-slot, included in the DLcommon burst, is being used to transmit data to the particular UE 120.

As shown by reference number 925, based at least in part on identifyingthat the mini-slot is being used to transmit the data to the particularUE 120, the particular UE 120 may receive the data within the mini-slotincluded in the DL common burst portion, and may process (e.g.,demodulate, decode, and/or the like) the data within the mini-slotincluded in the DL common burst portion of the slot.

In some aspects, based on receiving and processing the mini-slot data,the particular UE 120 may provide, to BS 110, an acknowledgement (e.g.,an ACK signal) and/or another type of response associated with the datatransmitted in the mini-slot. In some aspects, the particular UE 120 mayprovide the acknowledgment in the same slot as that of the mini-slot. Inthe case of an UL-centric slot, the particular UE 120 may provide theacknowledgement in the UL short burst portion or the UL data portion ofthe UL-centric slot. In the case of a DL-centric slot, the particular UE120 may provide the acknowledgment in the UL short burst portion of theDL-centric slot. Here, the acknowledgment may, in some aspects, be ajoint acknowledgment of both the data transmitted to the particular UE120 in the mini-slot and other data transmitted to the particular UE 120in the DL data portion of the DL-centric slot. This may occur when theparticular UE 120 receives two downlink grants (e.g., a downlink grantfor the mini-slot and a downlink grant for the data portion of the slot)and the particular UE 120 jointly acknowledges for both grants. In sucha case, BS 110 and the particular UE 120 need to agree that such a HARQconfiguration and acknowledgement reporting is allowed, which maynecessitate signaling between BS 110 and the particular UE 120. In someaspects, such signaling may be semi-static or dynamic, where the natureof the signaling may depend on a length, a duration, and/or an amount ofresources available in the UL-common burst portion of the slot.

In some aspects, the particular UE 120 may provide the acknowledgementin a subsequent slot.

In some aspects, if the data transmitted to the particular UE 120 usingthe mini-slot is not successfully receive and/or processed by theparticular UE 120 (e.g., causing the particular UE to provide a NACKsignal to BS 110), then BS 110 may retransmit the data. In such a case,BS 110 may retransmit the data in another mini-slot (e.g., included in aDL common burst portion of a later DL-centric or UL-centric slot) or ina DL data portion of a later DL-centric slot. Notably, the data need notbe retransmitted in another mini-slot.

As indicated above, FIG. 9 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 9 .

FIG. 10 is a flow chart of a process 1000 of wireless communication. Theprocess may be performed by a base station (e.g., the BS 110 of FIG. 1 ,access node 506 of FIG. 5 , apparatus 1102 of FIG. 11 , apparatus 1102′of FIG. 12 , and/or the like).

At 1010, the base station may schedule a mini-slot for transmission ofunicast data to a particular UE, the mini-slot being scheduled in aportion of a DL common burst portion of a slot. In some aspects, thebase station may identify control information the control informationmay include information that identifies a set of radio resourcescorresponding to one or more transmissions of data in a mini-slot in theDL common burst portion of the slot (i.e., a set of radio resources inthe control portion that will be used to transmit the data), informationthat identifies the particular UE to which the data is to betransmitted, and/or the like.

In some aspects, the base station may transmit the control informationwithin a control portion of a DL common burst. For example, the basestation may transmit the control information within a portion of a DLcommon burst portion of a DL-centric slot or an UL-centric slot. In someaspects, the particular UE may receive the control information and mayidentify that the particular UE is to receive the data in the mini-slotthat is included in the DL common burst portion of the slot.

At 1020, the base station may transmit a signal, including the unicastdata, within the mini-slot. In some aspects, the base station maytransmit a signal, including unicast data, destined for the particularUE, within the mini-slot (e.g., using other radio resourcescorresponding of the mini-slot) of the DL common burst portion of theslot.

In some aspects, the base station may transmit the control informationand the mini-slot data in a same slot (i.e., within a same DL commonburst of a DL-centric or UL-centric slot). Additionally, oralternatively, the base station may transmit the control information ina first slot (e.g., within a DL common burst portion of a DL-centric orUL-centric slot) and may transmit the mini-slot data in a second slot(e.g., within a DL common burst portion of a subsequent DL-centric orUL-centric slot). In some aspects, the particular UE may process thedata, included in the mini-slot within the DL common burst, based atleast in part on receiving the control information transmitted by thebase station.

In some aspects, the base station may schedule a mini-slot fortransmission of unicast data to a particular UE, wherein the mini-slotmay be scheduled in a portion of a DL common burst portion of a slot,and the base station may transmit a signal, including the unicast data,within the mini-slot.

In some aspects, scheduling the mini-slot may include identifyingcontrol information associated with scheduling the mini-slot, whereinthe control information may be transmitted, by the base station, withinat least one of another portion of the DL common burst portion of theslot or a portion of a DL common burst portion of another slot.

In some aspects, the base station may transmit a DMRS within themini-slot, and the DMRS may be used to demodulate data within a dataportion of the slot associated with the particular UE. Alternatively,the base station may transmit the DMRS within the data portion of theslot associated with the particular UE, and the DMRS may be used todemodulate data within the mini-slot. In such aspects, the DMRS and thedata should be pre-coded in a similar manner within both the mini-slotand the slot. In some aspects, signaling between the base station andthe particular UE may specify whether the DMRS signal transmitted withinthe mini-slot is to be used to demodulate data within a data portion ofthe slot, or whether the DMRS transmitted within the data portion of theslot is to be used to demodulate the unicast data within the mini-slot,wherein the signaling may be semi-static or dynamic depending onmobility of the particular UE or configurations (e.g., HARQconfigurations) of the mini-slot and the slot. In some aspects, if themini-slot transmission is required to acknowledged in a same slot as themini-slot, then the DMRS should be transmitted in the mini-slot ratherthan the data portion of the slot.

In some aspects, the mini-slot may be associated with a first frequencyrange and a second frequency range, wherein the first frequency rangeand the second frequency range are separated by a frequency range of acontrol portion of the DL common burst portion.

In some aspects, the mini-slot may be a first mini-slot, the unicastdata may be first unicast data, the particular UE may be a firstparticular UE, and the portion of the DL common burst portion may be afirst portion of the DL common burst portion, and the base station mayschedule a second mini-slot transmission of second unicast data to asecond particular UE. Here, the second mini-slot may be scheduled in asecond portion of the DL common burst portion, and the second unicastdata may be included in the signal within the second mini-slot. In someaspects, the first mini-slot may be associated with a first frequencyrange and the second mini-slot may be associated with a second frequencyrange, wherein the first frequency range and the second frequency rangeare separated by a frequency range of a control portion of the DL commonburst portion.

In some aspects, the unicast data may be associated with anultra-reliable low-latency communication service.

In some aspects, the slot is a DL-centric slot.

In some aspects, the base station may receive an acknowledgement,associated with the unicast data transmitted in the mini-slot, in an ULcommon burst portion of the slot, wherein the acknowledgement may beprovided by the particular UE. In some aspects, the acknowledgement maybe a joint acknowledgement that includes an acknowledgement associatedwith other data transmitted in a data portion of the slot. In someaspects, signaling between the base station and the particular UE maycause the base station and the particular UE to agree that a jointacknowledgment is permitted, wherein the signaling is semi-static ordynamic depending on a length, a duration, or an amount of resourcesavailable in the uplink common burst portion of the slot.

In some aspects, the base station may retransmit the unicast data withinat least one of a data portion of the slot, a data portion of anotherslot, or a mini-slot in the other slot.

In some aspects, a parameter, associated with the transmission of theunicast data within the mini-slot, may be different from a parameterassociated with the transmission of other data in a data portion of theslot, wherein the parameter may include a MCS or a number of MIMOlayers.

In some aspects, the slot may be an UL-centric slot. Here, anacknowledgement, associated with the unicast data transmitted in themini-slot, may be received in a data portion of the slot.

In some aspects, a length of the mini-slot may be one symbol or twosymbols. In some aspects, the length of the mini-slot may be implicitlysignaled to be the same as the length of the DL common burst portion ofthe slot. In this case, no explicit notification is needed regarding thelength of the mini-slot. In some aspects, the length of the DL-commonburst may be semi-statically configurable and, therefore, the length ofthe mini-slot may be adjusted accordingly. In some aspects, whether thelength of the mini-slot is the same length as the DL common burstportion of the slot may be determined based on signaling (e.g.,semi-static signaling) between the base station and the particular UE.

In some aspects, a frequency range of the mini-slot of the DL commonburst portion may differ from a frequency range used for a controlportion of the DL common burst portion of the slot.

In some aspects, the particular UE may not be not scheduled to receivedata in a data portion (e.g., a regular data portion) of the slot.

In some aspects, a UE may receive a signal, including unicast data,within a mini-slot, wherein the mini-slot may be received in a portionof a DL common burst portion of a slot, and the UE may process theunicast data within the mini-slot of the DL common burst portion of theslot. In some aspects, the UE may transmit a response, associated withthe unicast data, in the slot or in a subsequent slot.

Although FIG. 10 shows example blocks of a method of wirelesscommunication, in some aspects, the method may include additionalblocks, fewer blocks, different blocks, or differently arranged blocksthan those shown in FIG. 10 . Additionally, or alternatively, two ormore blocks shown in FIG. 10 may be performed in parallel.

FIG. 11 is a conceptual data flow diagram 1100 illustrating the dataflow between different modules/means/components in an example apparatus1102. The apparatus 1102 may be a base station, such as BS 110, 5Gaccess node 506, and/or the like. In some aspects, the apparatus 1102includes a reception module 1104, a scheduling module 1106, and/or atransmission module 1108.

The reception module 1104 may receive data 1110 from a network 1150,such as data transmitted by one or more one or more other networkentities. In some aspects, the reception module 1104 may provide data1112 to the scheduling module 1106. In some aspects, the data 1112 mayindicate that the scheduling module 1106 is to schedule, in a portion ofa downlink common burst portion of a slot, a mini-slot for transmittingunicast data to a particular UE. The scheduling module 1106 mayschedule, in a portion of a downlink common burst portion of a slot, amini-slot for transmitting the unicast data to the particular UE.

The scheduling module 1106 may provide data 1114 to the transmissionmodule 1108. For example, the scheduling module 1106 may provide data1114, including control information associated with scheduling themini-slot, to transmission module 1108. The transmission module 1108 maytransmit data 1116, including the control information to network 1150and/or to the particular UE within the slot. The data 1116 may alsoinclude the unicast data associated with the particular.

The apparatus may include additional modules that perform each of theblocks of the algorithm in the aforementioned flow chart of FIG. 10 . Assuch, each block in the aforementioned flow chart of FIG. 10 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

The number and arrangement of modules shown in FIG. 11 are provided asan example. In practice, there may be additional modules, fewer modules,different modules, or differently arranged modules than those shown inFIG. 11 . Furthermore, two or more modules shown in FIG. 11 may beimplemented within a single module, or a single module shown in FIG. 11may be implemented as multiple, distributed modules. Additionally, oralternatively, a set of modules (e.g., one or more modules) shown inFIG. 11 may perform one or more functions described as being performedby another set of modules shown in FIG. 11 .

FIG. 12 is a diagram 1200 illustrating an example of a hardwareimplementation for an apparatus 1102′ employing a processing system1202. The apparatus 1102′ may be a base station, such as BS 110, 5Gaccess node 506, and/or the like.

The processing system 1202 may be implemented with a bus architecture,represented generally by the bus 1204. The bus 1204 may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system 1202 and the overall designconstraints. The bus 1204 links together various circuits including oneor more processors and/or hardware modules, represented by the processor1206, the modules 1104, 1106, 1108, and the computer-readablemedium/memory 1208. The bus 1204 may also link various other circuitssuch as timing sources, peripherals, voltage regulators, and powermanagement circuits, which are well known in the art, and therefore,will not be described any further.

The processing system 1202 may be coupled to a communication interface1210. The communication interface 1210 provides a means forcommunicating with various other apparatus over a transmission medium.The communication interface 1210 receives a signal from via thetransmission medium, extracts information from the received signal, andprovides the extracted information to the processing system 1202,specifically the reception module 1104. In addition, the communicationinterface 1210 receives information from the processing system 1202,specifically the transmission module 1108, and based at least in part onthe received information, generates a signal to be applied to thetransmission medium. The processing system 1202 includes a processor1206 coupled to a computer-readable medium/memory 1208. The processor1206 is responsible for general processing, including the execution ofsoftware stored on the computer-readable medium/memory 1208. Thesoftware, when executed by the processor 1206, causes the processingsystem 1202 to perform the various functions described supra for anyparticular apparatus. The computer-readable medium/memory 1208 may alsobe used for storing data that is manipulated by the processor 1206 whenexecuting software. The processing system further includes at least oneof the modules 1104, 1106, and 1108. The modules may be software modulesrunning in the processor 1206, resident/stored in the computer readablemedium/memory 1208, one or more hardware modules coupled to theprocessor 1206, or some combination thereof. The processing system 1202may be a component of the BS 110 and may include the memory 242 and/orat least one of the TX MIMO processor 230, the RX processor 238, and/orthe controller/processor 240.

In some aspects, the apparatus 1102/1102′ for wireless communicationincludes means for scheduling a mini-slot for transmission of unicastdata to a particular UE, where the mini-slot may be scheduled in aportion of a DL common burst portion of a slot; and means fortransmitting a signal, including the unicast data, within the mini-slot.The aforementioned means may be one or more of the aforementionedmodules of the apparatus 1102 and/or the processing system 1202 of theapparatus 1102′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 1202 mayinclude the TX MIMO processor 230, the RX processor 238, and/or thecontroller/processor 240. As such, in one configuration, theaforementioned means may be the TX processor 230, the RX processor 238,and/or the controller/processor 240 configured to perform the functionsrecited by the aforementioned means.

FIG. 12 is provided as an example. Other examples are possible and maydiffer from what was described in connection with FIG. 12 .

It is understood that the specific order or hierarchy of blocks in theprocesses/flow charts disclosed is an illustration of exampleapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flow charts maybe rearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B,C, or any combination thereof” include any combination of A, B, and/orC, and may include multiples of A, multiples of B, or multiples of C.Specifically, combinations such as “at least one of A, B, or C,” “atleast one of A, B, and C,” and “A, B, C, or any combination thereof” maybe A only, B only, C only, A and B, A and C, B and C, or A and B and C,where any such combinations may contain one or more member or members ofA, B, or C. All structural and functional equivalents to the elements ofthe various aspects described throughout this disclosure that are knownor later come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed as a means plus function unless the element is expresslyrecited using the phrase “means for.”

1. An apparatus, a memory; and one or more processors coupled to thememory, the one or more processors and the memory being configured to:be scheduled to receive first data in a control portion, the controlportion comprising a number of symbols in a slot, the control portioncomprising a frequency band utilized for control information; bescheduled to receive second data in a second portion of the slot, thesecond portion of the slot being outside of the number of symbols, thefirst data and the second date being received on a second frequencyband; transmit an acknowledgement to acknowledge both the first data andthe second data.
 2. The apparatus of claim 1, the first data and thesecond data being received in a same slot, and the first data and thesecond data being received in the second frequency band, the frequencyband and the second frequency band being within a component carrierbandwidth.
 3. The apparatus of claim 1, the second frequency band beingwithin a component carrier bandwidth.
 4. An apparatus, a memory; and oneor more processors coupled to the memory, the one or more processors andthe memory being configured to: receive signaling specifying ademodulation reference signal (DMRS) signal in a control portion is tobe used to demodulate data within a second portion of the slot, thecontrol portion comprising a number of symbols in a slot, the controlportion comprising a frequency band utilized for control information,the second portion being outside of the number of symbols of the slot;receive the data in the second portion of the slot; receive the DMRS inthe control portion for demodulating the data; and demodulate the datausing the DMRS.
 5. An apparatus, a memory; and one or more processorscoupled to the memory, the one or more processors and the memory beingconfigured to: be scheduled to receive first data in a first frequencyrange, in a control portion, be scheduled to receive second data in asecond frequency range in the control portion; the control portioncomprising a number of symbols in a slot, the control portion comprisinga third frequency range utilized for control information; and receivethe first data in the slot.
 6. The apparatus of claim 5, the one or moreprocessor and the memory being further configured to: receive additionaldownlink (DL) data in the first frequency range, in a second portion ofthe slot, the second portion being outside of the number of symbols ofthe slot, the first data and the additional DL data being received in asame slot.
 7. The apparatus of claim 5, the one or more processor andthe memory being further configured to: receive the first data and thesecond data in a same slot.
 8. The apparatus of claim 7, the one or moreprocessors and the memory being further configured to: transmit anacknowledgement to acknowledge both the first data and the second data.9. The apparatus of claim 5, the one or more processors and the memorybeing further configured to: transmit uplink downlink (UL) data in asecond portion of the slot, the second portion being outside of thenumber of symbols of the slot, the first frequency range, the secondfrequency range, the third frequency range, and the UP data beingtransmitted within a component carrier bandwidth; the first data beingreceived and the UL data being transmitted in a same slot.
 10. Theapparatus of claim 5, the one or more processor and the memory beingfurther configured to: receive a retransmission of the first data in asecond portion of the slot, the second portion being outside of thenumber of symbols of the slot, the first data and the retransmission ofthe first data being received in a same slot.